Patent GB-254478-A (GB)
Title: An improved construction of brake mechanism for vehicle wheels
IPC: B60T11/04
Filed: 1925-06-04
Abstract: 254,478. Clark, D'A. M., (Bendix Brake Co.). June 4, 1925. Blocks acting on drums; compensating for wear; force-transmitting mechanism. - Steering- wheel brake mechanism for vehicles comprises a brake-shoe actuating means swivelling with the wheel and movable generally towards the axis of the steering pivot and an operating member not swivelling with the wheel but engaging the actuating means at a point which is moved to an operating position adjacent to but slightly spaced from the pivot axis so that the braking action is modified when the wheels are turned for steering. As shown in Figs. 1. 2, and 3, the brake comprises shoes 16, 22 mounted respectively on fixed pivots 18, 24, and a shoe 26 connected to the shoe 22 by a free pivot 30. The shoes 16, 26 are identical and interchangeable. Lateral displacement of the shoes 16, 26 is prevented by spring-urged washers 38, Fig. 3, mounted on pins 36 secured to the backing plate 20. The shoes are applied to the drum by a lever 46 pivoted on the shoe 26 and engaging a piece 52 on the shoe 16. The lever 46 is actuated by a lever 54 pivoted on the axle 14 and provided with a spherical end. The arrangement may be such that the points of contact of the levers 46, 54 of the two brakes when these are applied are at one side of the axis of the steering pivot so that the braking pressure is relieved on the outer wheel. In another form, Fig. 6, the shoes 16, 26 are applied by a cam 136 having a pivot 140 extending through the backing plate 122 and provided with a, serrated end to which is adjustably clamped the arm 138 engaged by the lever 146. The end of the pivot 140 is provided with flats 142 whereby it may be turned by a wrench into the applied position before securing the arm 138 in the required position. Fig. 7 .shows a suitable arrangement of operating mechanism where the space above the steering pivot is limited as in the case of a heavy lorry. The cam lever 230 is upturned and the lever 234 is fulcrummed on a pin secured to an inclined socket 236 on the head of the steering pivot 212. Figs. 8 and 9 show a further form comprising a shoe 315 pivoted at 316 to the backing plate 317 and a shoe 318 connected by a free pivot 319 to the shoe 315. A lever 321 pivoted at 323 on the backing plate has a stud 328 through which is threaded a rod 324 pivoted at 330 to a rod 325 screwing into the end of the shoe 318. A locknut 329 is provided on the rod 324 and the threaded end of the shoe 318 is slotted so that it may be clamped to the rod 325 by a screw 326. The pivot 330 is removable to permit of adjustment of the rods 824. 325. The connection between the lever 321 and the lever 322 pivoted on the axle comprises a ball 334 fitting loosely in a recess in the end of the lever 322 and bored to receive the cylindrical end of the lever 321. A further form comprises an arrangement of three shoes similar to that shown in Fig. 1, but operated bv a two-armed lever connected bv links to the ends of the shoes 16, 26 and having its lower end connected as shown in Figs. 8 and 9 to a lever 322.